DE19753424A1 - Valve actuation lever - Google Patents

Abstract

The invention relates to a valve operating lever having an oblong base body (1) which is formed without cutting and is shaped in an essentially symmetric manner relative to a longitudinal plane of symmetry (2) extending in a longitudinal direction of said base body. The inventive handle also comprises a valve contact area (20) arranged on a first end of the base body in addition to two shackles (25-26). The shackles are arranged in the valve contact area (20) on both sides of said longitudinal plane of symmetry (2), and each have a lateral surface (23, 24) which faces the longitudinal plane of symmetry (2), whereby the shackles (25, 26) are formed on the base body and are bent upwards toward the valve contact area (20). The shackles (25, 26) are arranged on an end edge (30) of the oblong base body (1) with a clearance (a) which is smaller than the clearance (b) of the lateral surfaces in the valve contact area (20). At least one of the shackles (25, 26) has a transition region (35, 36) extending away from the longitudinal plane of symmetry (2) in which the distance between the lateral surfaces (23, 24) increases. In addition, at least one of the shackles has at least one parallel region (37, 38) in which the lateral surfaces (23, 24) run essentially parallel to the longitudinal plane of symmetry (2).

Description

The present invention relates to a valve operating lever for transmitting the Movement of a cam arranged on a camshaft onto a gas exchange Valve of an internal combustion engine.

The object of the invention and its solution are described below using the example of a Roller rocker arm described. It should be noted that this description exercise is not to be understood as limiting the application of the invention, it is rather possible, the invention also with differently designed valve actuation beln such. B. with rocker arms or with non-roller-operated valve actuation levers to execute.

A roller rocker arm of the type in question is described in DE 195 43 657 A1 known.

The known valve actuation lever has a U-shaped base body on, at one end a pan-like depression is provided with which the lever supports in the installed state via a support element on the cylinder head. At the other end there is the valve contact area through which the gas exchange sel valve of the internal combustion engine depending on the position of the cam of the Noc kenwelle is actuated.

The cam is in a cam contact area with the valve actuation lever Contact, one in this cam contact area with a roller rocker arm roller is rotatably mounted by rolling elements.  

The base body of the valve actuation lever is formed without cutting and points to the End at which the valve contact area is provided, inwardly bent La that form lateral boundary surfaces.

Although this known valve actuation lever works very satisfactorily fulfilled, there is still a need to further increase the technical functionality, By the weight and thus the moment of inertia of the lever around its Axis of rotation is reduced without affecting the rigidity. Further there is a desire to further reduce manufacturing costs.

The present invention is therefore based on the object, a Ventilbetäti tion lever and in particular a roller finger follower and a method for the to provide its manufacture, in which the moment of inertia the lever around the axis of rotation is reduced. Another aspect of this task is it to design the valve actuation lever so that the rigidity against the State of the art increased and low manufacturing costs can be achieved.

This object is achieved by the subject matter of claim 1.

The method according to the invention is the subject of claims 12 and 13.

Preferred developments of the invention are the subject of the dependent claims che.

The valve actuation lever according to the invention has a substantially non-cutting shaped elongated body, preferably with a U-shaped profile. Of the The basic body is essentially symmetrical to itself in its longitudinal direction extending longitudinal plane of symmetry. On both sides of this longitudinal sym Metry level tabs are arranged in the valve contact area, each one have the side surface facing the longitudinal plane of symmetry. The tabs are on molded onto an end edge of this base body and towards the valve contact area bent over.

At least one of these tabs points away from this plane of longitudinal symmetry  away extending transition area in which the distance between the side faces enlarged and at least one parallel area in which this Side surfaces run essentially parallel to this longitudinal plane of symmetry.

The two tabs are at a clear distance at the end edge of the body pers arranged, which is less than the clear distance of the side surfaces in parallel area, this distance in each case in a direction perpendicular to the longitudinal symme operating level is determined.

The design according to the invention has a number of essential advantages.

The distance between the tabs on the end edge of the elongated body is a con structural size, which is the width of the elongated body in the valve contact area certainly. By reducing this distance, the width of the length is simultaneously union body at least in the valve contact area and thereby also its Weight decreased. Since the valve contact area radially from the axis of rotation of the Ven tilbethebels is spaced, this results in a substantial Verring tion of the moment of inertia around the axis of rotation of the lever. With that, the forces required to operate the lever are reduced at the same speed, and it becomes the permissible for the valve train with regard to the actuation forces Speed limit raised.

Since it is possible to reduce the width of the lever with the same dimensions like, the bending lengths of the lever are transverse to its longitudinal direction reduced, which can increase the rigidity.

Furthermore, the material costs are reduced by reducing the lever width, thereby reducing manufacturing costs. Compared to other manufacturing The chipless design, in which the tabs are also moved by a simple punching and bending process are produced, anyway considerable costs benefits.

Reducing the width of the lever also has the advantage that the valve train overall can build narrower. Because the engine designers due to the requirement Space economy and weight optimization are forced to make engines  Developing with the shortest possible overall length is not only particularly then of importance if due to the specifications for power, consumption and Exhaust levels three or more valves per cylinder are to be used.

In a first, preferred embodiment, the tabs are on the base body the bending process molded in such a way that they are parallel to the plane of longitudinal symmetry extend, d. H. run straight. The bending then takes place in such a way that one or both tabs to form the transition area from the longitudinal symmetry operating plane are bent away. At the end of the transition area, La then bent in such a way that the inner plane facing the plane of symmetry Side surface of the tab runs parallel to this.

Depending on the design requirements, this parallel area can then be used connect yet another constriction area in which one or both tabs are facing the longitudinal plane of symmetry again.

In a second, preferred embodiment of the invention, the tabs are the art punched that the transition area and the parallel area already with the deformed tabs are present. The tabs then only have to be reversed by 180 ° be bent and then show in the bent state, without further bending the desired contour in the valve contact area.

The first and the second embodiment can also be combined with one another the. In this case, the tabs are punched into an exit shape and then by a 180 ° bend and an additional bend to the longitudinal plane of symmetry or away from it into the final shape.

It is also possible to treat the tabs differently, so that z. Legs Tab is only subjected to a bend of approximately 180 °, while the other La both this bend and a further bend, in particular to the longitudinal experienced plane of symmetry or away from it. The initial form of Tabs be the same, e.g. B. the shape of an elongated cuboid with parallel to the longitudinal Corresponding longitudinal edges running at symmetry or below each other be different.  

Further advantages, features and possible uses of the present invention tion result from the following description of exemplary embodiments in Connection with the figures. In it show:

Fig. 1 is a bottom view of a first embodiment of the invention, which is designed as a rocker arm;

FIG. 2 shows a longitudinal section of the exemplary embodiment according to FIG. 1;

FIG. 3 shows a section through the illustration according to FIG. 2 along the lines III-III;

FIG. 4 shows a top view of the exemplary embodiment according to FIG. 1;

Seen Figure 5 is a view of the roller finger follower of the embodiment of Figure 1 during manufacture, from the bottom..;

FIG. 6 shows a representation corresponding to FIG. 5 in a further stage of production;

Figure 7 shows a second embodiment of the roller rocker arm according to the invention in a previous stage of manufacture, seen from below.

Fig. 8 hen the roller rocker arm according to FIG. 7 in a view from below.

A first embodiment of the invention will now be described with reference to FIGS. 1 to 6.

Fig. 1 shows a first embodiment of the Rollenschlepphe lever according to the invention.

The roller rocker arm has a base body, generally designated 1, which extends substantially symmetrically along a longitudinal plane of symmetry 2 . The term plane of symmetry is not to be understood in the purely geometrical sense here, but merely means that essential areas of the valve actuation lever are designed symmetrically to this plane of symmetry. The plane of symmetry 2 runs perpendicular to the drawing plane in the illustration according to FIG. 1 and forms the sectional plane in the illustration according to FIG. 2.

The elongated body is, as seen from the representation according to Fig. 3, designed essentially U-shaped and has a symmetrically extending to the symmetry plane 2 recess 4 in which a mounted on rolling elements 6 roll 7 is arranged. In the installed state, the roller 7 is in contact with the cam of a cam shaft.

In the right part of the illustration according to FIG. 1, a recess 10 for receiving egg nes (not shown) support element is provided. In the installed state, this element in turn is supported within the cylinder head (not shown). The design of this recess 10 is known in the prior art and therefore need not be discussed further here.

A valve contact area 20 is provided on the left side of the base body in the illustration according to FIG. 1. The valve contact area has a surface 21 , which is slightly convex in the exemplary embodiment, but can also have other curvature shapes or be flat.

The valve contact area is delimited by two lateral surfaces 23 , 24 facing the longitudinal plane of symmetry 2 , which are part of the tabs 25 , 26 .

The tabs 25 , 26 are formed on an end edge 30 of the elongated base body 1 , the end edge 30 being substantially perpendicular to the plane of symmetry 2 . The distance between the tabs 25 and 26 on this end edge of the base body corresponds to the length a in FIG. 5 between the arrows 31 and 32.

In the embodiment shown in FIG. 1, both tabs 25 , 26 have a transition region 35 , 36 in which the tabs extend away from the plane of symmetry 2 . A parallel area 37 , 38 adjoins this transition area 35 , 36 , in which both tabs run parallel to the plane of symmetry 2 . In the case of the tab 26 , this is followed by a narrowing region 40 in which the tab again runs towards the plane of symmetry 2 .

The term transition area is therefore defined by the fact that the angles moderate alignment of the tab or the side surfaces with respect to the longitudinal sym level changes.

In the parallel area 37 , 38 , the distance between the two tabs corresponds to the distance b, as shown between the arrows 42 , 43 . This distance b is greater than the stand a. The difference between the two routes corresponds essentially to the savings in width of the base body compared to the prior art discussed at the outset.

In the embodiment shown, the two tabs 25 , 26 , as shown in particular in the illustration in FIG. 2, lie flush, ie without a space, on the curved surface of the valve contact region 20 .

Deviating from this, the tabs in this embodiment and also in the next embodiment can be designed such that a gap is provided between the tabs and the surface of the valve contact area, the tabs then being shaped such that their end area rests on the valve contact area. Around the end region, in the illustration according to FIG . B. in the tab 26 of the constriction area 40 , with respect to the valve contact area, can be fixed both in the first alternative, that is, in the case of flush-fitting tabs, and in the second alternative, that is, in the case of tabs that are at some distance from the valve cone have cycle area, at the end of an additional connection, preferably be made by a welding point.

A method of manufacturing this embodiment of the invention will now be explained with reference to FIGS. 5 and 6.

The roller rocker arm shown in the exemplary embodiment is punched out of a metal sheet as a whole and then preferably cold-formed in order to achieve the final design shown in FIGS. 1 to 4. The tabs 25 and 26 are formed during punching as an essentially straight extension of the base body 1 . Then, as shown in Fig. 6, they are formed downward (seen in the Dar position of the drawing), the distance between the tabs further corresponding to the distance a. The tabs are then bent away from the symmetry plane 2 to form the transition region 35 , 36 . This bending process is carried out in such a way that the tabs are initially bent outwards at a first bending angle, so that the first part of the transition region 35 , 36 which runs away from the plane of symmetry 2 forms and that the tabs then connect in such a direction the plane of symmetry 2 are bent back so that the further part of the tabs runs parallel to the line of symmetry 2 . Only one or both ends of the tabs, as indicated by 40 in Fig. 1, is again formed with a bending angle inwards, on the plane of symmetry 2 .

As the illustration according to FIGS. 1 to 6 shows, this design makes it possible to design the valve actuation lever with a small width. This saves a lot of material, which reduces the mass moment of inertia around the axis of rotation and increases the stiffness while maintaining the same dimensions.

Another embodiment of the invention will now be explained with reference to FIGS. 7 and 8.

In this exemplary embodiment, the end product essentially shown in FIG. 8 corresponds to the roller finger follower, essentially the representation according to FIG. 1. Corresponding reference numerals are therefore also used there.

However, there is a difference in the design of the tabs 51 and 52.

As shown in FIG. 7, the tabs are immediately formed during a punching operation in such a way that the desired transition area already arises during the punching process and not, as in the embodiment according to FIGS. 1 to 6, during bending.

The tab 51 is integrally formed on the end edge 30 of the base body 1 which extends essentially perpendicular to the plane of symmetry 2 . The tab 51 has a first area in which the tab forms an acute angle, designated 53, to this end edge 30 even in the undeformed state, thereby forming a transition area 54 pointing away from the longitudinal plane of symmetry 2 . The transition region 54 is followed by a parallel region 55 , which is designed parallel to the longitudinal plane of symmetry and thereon an area 56 in which the side surface is directed at an acute angle to the longitudinal plane of symmetry.

In the bracket 52 , a parallel region 57 is initially provided, which runs parallel to the longitudinal plane of symmetry 2 , to which the transition region 58 then closes, in which the tab runs away from the longitudinal plane of symmetry 2 to the outside. This is followed by a further parallel region 59 , which runs parallel to the longitudinal plane of symmetry 2 and which forms the side surface 60 .

The method for producing this valve actuation lever is designed similarly to that in the exemplary embodiment described above. Here, too, the tabs are bent by approximately 180 °, which results in a design of the rocker arm according to FIG. 8. However, the bend directed towards or away from the longitudinal symmetry plane is omitted here. The punching tool is designed somewhat more complex than in the exemplary embodiment according to FIGS. 1 to 6. However, this is offset by the advantage that the bending process is easier.

Reference list

1

Basic body

2nd

Longitudinal plane of symmetry

4th

Recess

6

Rolling element

7

role

10th

deepening

20th

Valve contact area

21

area of

20th

23

,

24th

Lateral surface

25th

,

26

Tab

30th

End edge

31

,

32

arrow

35

,

36

Transition area

37

,

38

Parallel area

40

Narrowing area

42

,

43

arrow

51

,

52

Tab

53

acute angle

54

Transition area

55

Parallel area

56

Narrowing area

58

Transition area

59

Parallel area

60

side surface
a Distance perpendicular to the plane of longitudinal symmetry
b Distance perpendicular to the plane of longitudinal symmetry

Claims (14)

1. Valve actuating lever for transmitting the movement of a cam arranged on a camshaft to a gas exchange valve of an internal combustion engine with:
an essentially non-cutting elongated base body ( 1 ) which is essentially symmetrical to a longitudinal plane of symmetry ( 2 ) extending in its longitudinal direction,
a valve contact area ( 20 ) arranged at a first end of this base body,
Two tabs ( 25 , 26 ; 51 , 52 ) arranged on both sides of this longitudinal plane of symmetry in the valve contact area, each of which has a side surface ( 23 , 24 ; 60 , 61 ) facing the longitudinal symmetry plane, these tabs being molded onto this base body and closed this valve contact area are bent over,
characterized by
that these tabs are arranged on an end edge ( 30 ) of this elongate base body with a clearance (a) which is less than the clearance from (b) of the side surfaces in the valve contact area, the distance in each case in a direction perpendicular to Longitudinal plane of symmetry is measured, and
that at least one of these tabs has at least one transition region ( 35 , 36 ; 54 , 58 ) extending from this longitudinal plane of symmetry, in which the distance between these side surfaces increases and at least one parallel region ( 37 , 38 ; 55 , 59 ), in which these sides are essentially parallel to this plane of longitudinal symmetry. 2. Valve actuating lever according to claim 1, characterized in that this transition region ( 35 , 36 ) is created by a plastic deformation. Valve actuating lever according to claim 2, characterized in that this transition region ( 54 , 58 ) is created by a material-separating operation. 4. Valve actuation lever according to at least one of the preceding claims, characterized in that at least one of these tabs has a constriction area ( 40 ) adjoining this parallel area, in which the tab is formed tapering towards the longitudinal plane of symmetry ( 2 ). 5. Valve actuation lever according to at least one of the preceding An sayings, characterized that this body in a sectional plane that is perpendicular to the longitudinal symme trieebene lies, is substantially U-shaped. 6. Valve actuation lever according to at least one of the preceding An sayings, characterized, that these tabs are rectangular in cross section and preferably square are trained. 7. Valve actuating lever according to at least one of the preceding claims, characterized in that the valve contact region ( 20 ) forming surface ( 21 ) is curved and that the tabs are bent such that they rest on this surface following the curvature. 8. Valve actuating lever according to at least one of claims 1 to 6, characterized in that the valve contact region ( 20 ) forming surface ( 21 ) is curved and that the tabs are bent such that they are at a distance from this surface in a partial area and only lie on this surface at their end area. 9. Valve actuation lever according to claim 7 or 8, characterized in that this curvature is at least partially a convex curvature. 10. Valve actuation lever according to at least one of the preceding An sayings, characterized, that this valve lever is designed as a rocker arm. 11. Valve actuation lever according to claim 10, characterized in that that this valve actuating lever is designed as a roller rocker arm. 12. Valve actuating lever according to claim 11, characterized in that this roller rocker arm has a roller ( 7 ) rotatably mounted via rolling elements ( 6 ). 13. A method for producing a valve actuation lever and in particular a valve actuation lever according to one of claims 1 to 12 with the following method steps:
Punching out an elongated base body ( 1 ), which is designed essentially symmetrically to a longitudinal symmetry plane ( 2 ) extending in its longitudinal direction, with two tabs ( 25 , 26 ) arranged on either end of this longitudinal symmetry plane, each of which is one of the Have side surface facing the longitudinal plane of symmetry, these tabs being formed on this base body and running parallel to this longitudinal plane of the plane,
Bending these tabs through an angle of approximately 180 °,
Bending at least one of these tabs to form a transition region ( 35 , 36 ) extending from this plane of longitudinal symmetry, in which the distance between these side surfaces increases, and at least one parallel region, in which these side surfaces run essentially parallel to this plane of longitudinal symmetry. 14. A method for producing a valve actuation lever and in particular a valve actuation lever according to one of claims 3 to 12 with the following method steps:
Punching out an elongated base body ( 1 ), which is designed essentially symmetrically to a plane of longitudinal symmetry extending in its longitudinal direction ( 2 ), with two tabs ( 51 , 52 ) arranged on either side of this plane of longitudinal symmetry, each of which has a side surface facing the plane of longitudinal symmetry have, these tabs are integrally formed on this base, and wherein at least one of these tabs has at least one extending from this plane of longitudinal symmetry Rich in which the distance between these side surfaces increases and at least one parallel area in which these side surfaces essentially run parallel to this plane of longitudinal symmetry,
Bend these tabs through an angle of approximately 180 °.